The present invention relates to a semiconductor device manufacturing technique and more particularly to a technique applicable effectively to the step of dividing a semiconductor wafer affixed to a dicing film into plural semiconductor chips and thereafter separating the semiconductor chips from the dicing film and the step of mounting each of the separated semiconductor chips onto a mounting base through a die bonding paste.
As steps included in a process of mounting a semiconductor chip (hereinafter referred to simply as “chip”) onto a mounting base such as a wiring substrate or a lead frame to assemble a semiconductor package there are a pickup step of separating a chip from a semiconductor wafer (simply as “wafer” hereinafter) and picking it up and a pellet bonding step of bonding the picked-up chip onto a mounting base. The pickup step and the subsequent pellet bonding step are also called die bonding steps.
In the pickup step, dicing is performed in a state in which a dicing tape is affixed to the back surface of a wafer with a desired integrated circuit formed thereon, to divide the wafer into plural chips. Next, the chips are peeled off one by one while pushing needles or the like against the back surface of the dicing tape and thereafter each chip is conveyed onto a mounting base while being held by a collet.
In the next pellet bonding step, paste (adhesive) for die bonding is fed onto the mounting base with use of a paste applicator called a dispenser and the chip is bonded onto the mounting base through the paste. There also is known a method wherein a filmy adhesive material called die attach film is affixed beforehand to the back surface of a semiconductor chip and the chip is bonded onto a mounting base through the die attach film. In case of using the die attach film, dicing is performed while affixing both die attach film and dicing tape to the back surface of a wafer in the pickup step. Then, the divided chips are separated from the dicing tape together with the die attach film and are each conveyed onto the mounting base.
Japanese Unexamined Patent Publication No. 2004-146727 (Patent Literature 1) discloses a technique wherein a wafer on a wafer sheet is diced and thereafter the wafer sheet is expanded to divide the wafer into chips.
Japanese Unexamined Patent Publication No. Hei 11(1999)-214487 (Patent Literature 2) discloses a technique of expanding a wafer sheet by means of a locking ring.
Japanese Unexamined Patent Publication No. 2004-273895 (Patent Literature 3) and No. 2004-193241 (Patent Literature 4) disclose a technique of dividing a wafer affixed to a die attach film into chips.
Japanese Unexamined Patent Publication No. 2000-265943 (Patent Literature 5) and No. 2002-346462 (Patent Literature 6) disclose a technique wherein a scraping groove is formed in the outer periphery of a sealing disc connected to a plunger pump of a paste applicator, and paste leaking from a sealing surface is collected into the scraping groove, thereby improving the adhesion of the sealing surface.
Japanese Unexamined Patent Publication No. Hei 9(1997)-162205 (Patent Literature 7) discloses a technique of detecting a state of contact or non-contact between a dicing table and a needle with use of an electric circuit using a magnet.
Japanese Unexamined Patent Publication No. Hei 11(1999)-344536 (Patent Literature 8), No. Hei 11(1999)-183573 (Patent Literature 9), No. 2000-147063 (Patent Literature 10) and No. 2003-121494 (Patent Literature 11) disclose a technique of semi-fixing a probe testing needle with a magnet.